To Determine the Validity of the Sebia HbA1c Assay for Identifying Variant Haemoglobin Disorders

The purpose of this research is to determine if the Sebia HbA1c programme can be used to accurately identify patients with a variant haemoglobin chain. While this method is not currently validated as a diagnostic test for haemoglobin variants, it is a validated diagnostic test for diagnosing diabetes through the measurement of HbA1c. HbA1c testing is already part of the prenatal screening service to assess the risk of gestational diabetes in the Waikato and Bay of Plenty regions in New Zealand. However, as it is not a diagnostic test for variant haemoglobin detection, when an abnormal peak is detected, it is up to the clinician to order further tests to accurately identify the abnormal haemoglobin chain, resulting in increased costs and turnaround times for results. The only current diagnostic test is the Sebia Haemoglobin E method. Data used in this study were from routine requests for haemoglobinopathy identification using the Sebia Haemoglobin E programme. These samples were run in parallel with the Sebia HbA1c programme to determine the difference between migration patterns and quantitation of haemoglobin peaks between both methods. The results of this study demonstrate a good correlation between the two methods with a correlation coefficient of at least 0.9, however the HbA1c method shows a negative bias when compared to the reference method: the Haemoglobin E method. Despite this, laboratories could use the HbA1c technique as a presumptive method for identifying abnormal haemoglobin chains, provided adjustments to the reference intervals were made